Electrical apparatus and electronic devices such as computers and mobile phones may operate at different operating voltages from an electrical source. Accordingly, electrical power is required to be stepped up or down to a suitable operating voltage for different electronic devices. Each of these apparatus or devices may comprise different operating modules which operate at different operating voltages, hence multiple power converters may be also included in these apparatus or devices.
In these electronic devices, power converters such as switching converters may be used to convert the electrical power to a required operating voltage. During the power conversion process, switches in the switching converters may be turned on and off periodically, and hence current ripples are induced in the switching converter. Such operation may also reduce the power factor of the electronic devices, and more seriously, introducing a significant harmonic distortion to the power source. Hence correction circuits may be placed between the power converters and the power sources to improve the performance of the power electronic system.